Martyniuk Bartosz, Morasiewicz Piotr, Wudarczyk Sławomir, Dragan Szymon Feliks, Filipiak Jarosław
Wrocław University of Science and Technology, Department of Biomedical Engineering, Mechatronics and Theory of Mechanisms, Łukasiewicza 7/9, 50-371 Wrocław, Poland.
Wrocław Medical University, Department and Clinic of Orthopaedic and Traumatologic Surgery, Borowska 213, 50-556 Wrocław, Poland.
Clin Biomech (Bristol). 2019 Mar;63:79-84. doi: 10.1016/j.clinbiomech.2019.02.020. Epub 2019 Feb 27.
The mechanical parameters of the Ilizarov fixator are influenced by many factors related to its spatial configuration. The aim of this study was to experimentally evaluate the impact of the type of implant and the number of distraction rods on the uniformity of loading of distraction rods and stiffness coefficients of the Ilizarov fixator.
The tests were carried out on a physical model. The model was mounted in a universal loading station MTS 858 Mini Bionix. Forces in distraction rods are measured with the use of strain gauge force transducers. Displacements of bone fragments were measured by means of digital image correction.
In the case of a fixator with 3 distraction rods, configuration of implants has no statistically significant effect on the forces occurring in distraction rods. In the case of a fixator with 4 distraction rods, there are statistically significant differences in the forces in distraction rods. The highest transverse stiffness coefficients occurs in the system with 4 distraction rods and the configuration of 1K1S implants, while the smallest transverse stiffness coefficients occurs in the fixator with 4 distraction rods and the configuration of 0K1S implants.
Based on the results of experiments on the physical model, we observed an asymmetry in the distribution of forces transmitted through distraction rods. The configuration with 3 distraction rods provides more uniform distribution of forces in distraction rods and reduces the impact of the implant configuration on transverse stiffness coefficients. The use of a configurations with 4 rods may be advantageous when we want to obtain greater transverse stiffness coefficients of a system consisting of the fixator and fragments of the lengthened bone.
伊里扎洛夫固定器的力学参数受许多与其空间构型相关的因素影响。本研究的目的是通过实验评估植入物类型和牵张杆数量对牵张杆加载均匀性以及伊里扎洛夫固定器刚度系数的影响。
在物理模型上进行测试。该模型安装在MTS 858 Mini Bionix通用加载台上。使用应变片式力传感器测量牵张杆中的力。通过数字图像校正测量骨块的位移。
对于具有3根牵张杆的固定器，植入物构型对牵张杆中产生的力没有统计学上的显著影响。对于具有4根牵张杆的固定器，牵张杆中的力存在统计学上的显著差异。横向刚度系数最高出现在具有4根牵张杆和1K1S植入物构型的系统中，而最小的横向刚度系数出现在具有4根牵张杆和0K1S植入物构型的固定器中。
基于物理模型的实验结果，我们观察到通过牵张杆传递的力分布不对称。具有3根牵张杆的构型在牵张杆中提供了更均匀的力分布，并降低了植入物构型对横向刚度系数的影响。当我们希望获得由固定器和延长骨碎片组成的系统更大的横向刚度系数时，使用具有4根杆的构型可能是有利的。
